US2689018A - Apparatus and method for deaerating water - Google Patents

Description

Sept. 14, 1954 A. E. KITTREDGE 2,689,018

APPARATUS AND METHOD FOR DEAERATING WATER Filed June 11, 1951 3 Sheets-Sheet l .FJGJ 40 41 42 11 I I I I I 1 l l l l l l l ATTORNEYS.

p 1954 A. E. KITTREDGE APPARATUS AND METHOD FOR DEAERATING WATER 3 Sheets-Sheet 2 Filed June 11 1951 ATTORNEYQ p 1954 A. E. KITTREDGE APPARATUS AND METHOD FOR DEAERATING WATER 3 Sheets-Sheet 3 Filed June 11, 1951 Patented Sept. 1 4, 1954- APPARATUS AND METHOD FOR DEAERATING WATER Arthur E. Kittredge, Audubon, N. J., assignor to American Water Softener 00., Philadelphia, Pa., a corporation of New Jersey Application June 11, 1951, Serial No. 230,951

11 Claims.

This invention relates to apparatus and method for deaerating water, and more particularly for preheating and deaerating water.

It has previously been proposed to provide a water deaerator wherein the air and other relatively noncondensible gases are separated from the water by the direct contact scrubbing action of steam. In certain instances the steam remaining after completion of the scrubbing or deaerating process is separated from the deaerated water and recycled for countercurrent direct contact with the water entering the apparatus, thereby utilizing the heat of the recovered steam to preheat the water. One example of such apparatus is shown in my prior U. S. Patent No. 1,951,024, issued March 13, 1934. Another device of somewhat similar character is disclosed in the U. S. patent to Gibson et al. No. 1,951,015, issued March 13, 1934.

In conventional water deaerating devices, reat emphasis has been placed upon the feature wherein a tortuous path is provided for the steam and water in the deaerating section of the apparatus, such construction being generally accepted as superior from the standpoint of deaerating efficiency. However apparatus of this character is subject to the objection that a relatively high pressure drop is encountered by reason of the fluid flow through the tortuous passages. Moreover the prior art devices have been relatively expensive to manufacture and the tortuous passage elements diflicult to maintain.

In deaerating apparatus having a preliminary preheating chamber for preheating the incoming water, it is conventional to provide a water seal between the preheating section and the deaerating section of the apparatus. Because of the relatively great pressure drop of the steam passing through the deaerating stage, it has been necessary to provide a relatively deep water seal to overcome the pressure loss imposed upon the steam before it reaches the preheating compartment.

Still another difficulty encountered is that the water heating and deaerating apparatus of the prior art has a limited capacity in proportion to its size and is relatively expensive to manufacture, operate and maintain.

It is accordingly an object of the invention to provide an improved apparatus and method for deaerating water. Another object of the invention is to provide a relatively compact apparatus characterized by improved efliciency and capacity for deaerating water. Still another object is to provide an efficient, high capacity method for deaerating water with steam and preheating the water to be deaerated by transferring heat to it from the steam recovered from the deaeration process. Other objects are to provide method and means for minimizing or overcoming the .effect of pressure drop as the steam passes through the deaeration stage of the process, and for providing means for transferring heat from the vent steam to the incoming water. Other objects and advantages of the invention including the simplicit economy, and ease of operation and maintenance in accordance with the invention will further be apparent hereinafter, and in the drawings whereof:

Fig. 1 represents a side elevation of water deaerating apparatus constituting one embodiment of the invention.

Fig. 2 represents an enlarged fragmentary side elevation of the central portion of the apparatus of Fig. 1.

Figs. 3 and 4 represent sectional views taken as indicated by the lines and arrows III-III and IV-IV which appear in Fig. 1.

Fig. 5 represents a sectional view taken as indicated by the lines and arrows V-V which appear in Fig. 3. 1

Fig. 6 represents an enlarged fragmentary side elevation of the upper portion of the apparatus of Fig. 1, and

Fig. 7 represents a sectional view taken as indicated by the lines and arrows VIIVII which appear in Fig. 6.

It will be appreciated that the foregoing drawings and the following description relate to one specific embodiment of the invention, and that numerous modifications may be made without departing from the scope of the invention.

Referring now to the deaerating heater con- I structlon shown in the drawings, the number Ill designates a tank having a water inlet pipe II at its top, steam inlet pipe I2 and water overflow pipe I3 on its side, deaerated water outlet pipe 14 and drain line 15 on its bottom, and a vent l6 for the relatively non-condensible gases, principally air. Mounted in a neck I! at the top of tank In is a nozzle structure comprehensively designated 20 serving to introduce the water in the form of a spray into a water preheating section 21 of the tank I0. Below the water preheating section 2I is a deaerating section 22, further to be described in detail.

Bolted to the flange 23 of neck I! is a cover plate 24 having a central aperture in registry with the opening in the water inlet pipe I I, which is bolted to the top of cover plate 24. A cylindri- 3 cal plate 25, concentric with tank Ill, see particularly Figs. 1, 6, '7, is formed integrally with a top plate 26 which is bolted tocover plate 24 and to water inlet pipe H. A depending tube 21 is formed integrally with top plate 26 in alignment with the opening in water inlet pipe H, the top plate 26 having an aligned central opening to provide free communication between pipe I i and depending tube 21.

Supported on and welded to the top plate 26 and depending tube 21 are four upper wings 30 formed integrally with an upper ring 3| through which is disposed a vertical sleeve 32 having a top flange 33 overlapping the top face of ring 3!, and thus supported by ring 31. The vertical sleeve 32 also has a bottom flange 3Q supporting a lower ring 35 to which are ,aflined {our lower Wings 36. Wings 36 are aflixed to a depending cylinder 31 which is concentric with, and has substantially the same diameter as, the depending tube. 2.1. A helical spring 3.8 normally under. compression, surrounds the sleeve 32 and bears againstv rings 3| and 35.. A vertical shaft 40 is slidably disposed within the sleeve 32 for movement up and down, and has a fixed nutv ll Howmove the vertical shaft 40 downwardly together with va .4.3=.and: ylin er 3.1. provi in a u stantially horizontally directed fanned vent condenser; spray- ,S cxtendingin all directions comnletelv across the area enclosed within the annular plate 25, in the region of the neck il' of tank it, After. y i de ea h s me hanica to shou der 1t e alve is o ed, ro di a conical water spray S which is directed downardl n the d l r-sting sec io -1.1 1% ta k. Hi- The cover plate 24 and top plate 26 havealigned apertures forming a vent I6 accommodating. a,

vent pipe, 45.v through; which; air a-nd othernoncompressiblegases, are vented to the. atmosphere. Vent pipe 45 is welded to cover plate 2A.,

An outer baifle. ring 46 is welded to; the inner surface of annular plate 2 and four web; strips 4-7 are weldedftothe same inner surface andtoh a fl ing a n. nn b ie n a r e s diameter than outer baffie ring 46, and. disposed belowit; is. welded to each of the web strips. #53 and supported thereby, at a pointslightly above thefbo'ttom endof the depending tube 27 The hafile rings 46, 50. are thus disposed. intermediate the. spray-S and. ventpipe 4 5, and'serve. tokeep;

spray from entering the vent pipe li. Beferring now more particularly toFigs, 1 -5;

.11% i and. n n t condui 5 s e within thesteampipe |2;., Bottom; plate 52 carriesa gasketed handhole. cover. 54;.for. thehanda. leiifi 'li erce ptaclei 5] is supported wit-him 7 e drawings, the number 5.1. designates an; gl tcylindrical receptacle. concentric with. tank [0, having a bottom-plate 5 2;belowthesteam the walls of tank It by the upper and lower spacer" strips 56. Thus there is provided an annular space 5'! between the receptacle 5| and tank I0. The cylindrical side wall of. receptacle 5|. terminates at its upper end at substantially the same level as the bottom edge of the cylindrical plate A shelf ring 66 is aflixed to the insideface of receptacle 5! below the deaerating section 2 I. A plurality of separate shelf plates 6! are bolted to the shelf ring 60, with sealing gaskets therebetween, each shelf plate 6| having a raised strip 62 fixed to it and overlapping the next adjacent shelf plate 6! of the group. A yieldable gasplates 6 I in the valve 43 is closed and the cylinder 3,! is in contact with thedehending, tube 2]. ever water under pressure introduced through water inlet pipe H is effective upon valve it to hot 59 (Fig. 5) is compressed between each raised strip 62 and the shelf plate 65 beneath it, forming water-tight seals between the individual shelf The shelf plates 6! have a central opening 63 within which is inserted an inside water pipe 64 having top, flanges 65 bolted to the shelf. plates 6|. with gas ets n osed-. 2 for a. seal. A distributor t y 1 hav n a e ati-v lv heavy horizontal pla e and upr h cy indrical; inner wall 16 is aflixed to the inside face of receptacle 5! below the shelf plates 6!, thus forming an annular chamber 69 in the receptacle 5t. Supported on top of the wall 16 bymeansof hangers H is a Water receptacle "[2 having a closed bottom below the bottom edge of inside water pipe 64. but open at the top The waterseal receptacle 12 has a top flange ?3.-space d-in1-- mediately below the shelf plates 6i by spacer webs M which also constitute support members; for the shelf plates 61, and the inside watfirpipe 64. Top flange 73 has an. integral extension. flange 1-5 which has downwardly and outwardly.- inclined top and bottomfaces it, 'll.

Thehorizontal plate 67. of the. distributon tray- 66 has a stiffener plate 66 immediately below i-t,. and the plates 67, are provided with apertures accommodating a plurality ofheat exchangers in. the form of vertical wetted-wall tubes BL. Tubes 81. are also disposed through corresponding; apertures. in the bottom: plate 5.2 of recep tacle ill. The tubes 8 I have narrow. vertical notches 82 all at substantially the same level above the stiffener plate. 81!, inthe form of weirs: through which the? water flows into the tubes 83!. from distributor tray 66. I

The bottom portion 83, of tank it: constitutes a water storage section with a separation charm-e ber 79 above the water level in the chamber;83-,v Overflow pipe l3. supports a. cap 8-4;. spaced directly above the; opening of pipe; 13;; by bars= .5;.

ap 84 erves s, a; s i d; defiet ne the combi ed;

water and steam I from tubes; 8i preventing; them;

from. entering the; overflow pipe. l3 A large;

it downwardly and permitting cylinder 3'7 60.511136:

downwardly, away from; depending: tube; 2:7,. thus xs o idi the ray: tion of water pressure drives. valve.- 43 further:-

downwardly, away. from; cylinderwhich is. then supported by flange:3.4',. thus forming S; The spray S". is collectledron the annularplate 25: and drops verticallyfromi. it; intersecting thepath. of main. water spray,- S andimix-ingwith The. mixed: water is.collected:oni the shelf formed by; shelf: plates.fiiaand overflows, as indicated-by the arrow la), into the central opening fit in pipe 64:. Thiawatenis collected in watenseal't Furtherapplica'r receptacle I2 and flows over the flange 13 and the top face 16 of flange l5, eventually dropping to the distributor tray 66, overflowing the weirs formed by notches 82, and downwardly within the tubes 8| to the deaerated water storage chamber 83.

Steam entering through pipe l2 flows transversely across the vertical tubes and upwardly as indicated by the arrows (1)) through the narrow annular space 90 between the upright cylindrical inner wall 10 and the wall of water receptacle 12. At the top of the annular space 90 the steam turnssharply outwardly by reason of flange 13. The steam emerging from the circular radial discharge port entrains fluid from the outlet of the water seal. The steam jet ore-'- ates a suction efiect on the outlet of the water seal. The mixed water and steam flow under violently turbulent conditions downwardly through'tubes 8| with further direct heat-interchange and removal of air and other gases from the water, and the steam and gases separate from the water which settles in separation chamber 19. The steam and air flow upwardly through the annular space 51, into the neck portion of the tank. Some of the steam flows at an angle through the water spray S, preheating the water. The entrained air and other gases travel with the steam upwardly inside the annular plate 25 and through the vent condenser spray S in which some of the remaining steam is condensed.

It is of particular importance to observe that the jet action of the steam, in combination with the condensing action of the water on the steam at the edge of extension flange creates a slight suction on the water seal outlet. While in conventional deaerating heaters a water seal of about 18 inches head and above has been required, the apparatus may be so designed that,

for particular water and steam flow rates, a relatively low pressure differential is effective upon the water seal.

The particular construction embodying the wetted wall tubes BI is highly advantageous, in that means are provided wherein the preheated water is deaerated by intimate contact with steam under conditions of high turbulence on both the steam and water inside the tubes, while concurrently heat is transferred through the tube walls to bring the water being deaerated closer to the boiling point, or even under oertain conditions to cause actual evaporation within the tubes.

The particular construction of the apparatus is also of real advantage. The relatively heavy horizontal plate 61, coacting with stiflener plate 80, serves not only as a sealed trough for water distribution, but also as a support for the water seal receptacle 12. Moreover the vertically disposed tubes 8|, together with bottom plate 52 of cylindrical receptacle 5| further coact with the foregoing elements to provide structurally rigid support means for the shelf Plates 6| as well as the inside water pipe 64 and water seal receptacle 12, eliminating the weight and expense of additional structural support members, and providing substantially unobstructed free space in the deaerating section 2|, and above the distributor trough 66. Moreover, by reason of this construction the apparatus may readily be wholly or partially dismantled for cleaning, repair or replacement of parts.

While I have disclosed my invention with reference to one embodiment thereof, it will be apparent to those skilled in the artthat" changes may be made in the form of the apparatus specifically described herein, including reversals of parts and substitutions of equivalent mechanisms, and that certain features of the invention may be used to advantage without the use of other features, all without departing from the spirit of the invention as defined in the annexed claims.

Having thus described the invention, I claim:

1. In apparatus for deaerating water, a tank, means for introducing water into said tank, means including a Water seal through which said Water flows, said water seal having a restricted outlet including a downwardly inclined flange supporting the water flowing, out of said seal, a mixing chamber in said tank arranged to receive the water from said inclined flange member, vertical tubes connected to said mixing chamber and extending downwardly therefrom, a steam chamber through which the tubes pass, a separation chamber below said steam chamber said separation chamber being connected to said tubes, means for introducing steam into said steam chamber, and means providing a restricted passage disposed between said water seal and mixing chamber connecting said steam chamber to said mixing chamber at a point immediately below said downwardly inclined flange.

2. Apparatus for deaerating water comprising a water preheating chamber, a mixing chamber, a vent on said preheating chamber, a water spray nozzle in said preheating chamber comprising a pair of coaxial cylinders movable toward and away from one another to form a slot below said vent means, means for introducing water under pressure to one of said cylinders to form a spray through said slot, limit means governing the extent of. movement of said cylinders away from one another, means on one of said coaxial cylinders coacting with said limit means to provide a second water spray directed into said preheating chamber, means for conducting the sprayed water into said mixing chamber, means for introducing steam into the mixing chamber to deaerate said water, walls forming a separate space below said mixing chamber for separating the steam'and air from said deaerated'water, and a conduit carrying said separated steam into said preheating chamber for passage through both said sprays.

3. The invention defined in claim 2, further characterized by the provision of bafile plates between the vent means and the slot between said coaxial cylinders.

4. The invention defined in claim 2, further characterized by the provision of an annular wall disposed outside said nozzle, inside the wall of the preheating chamber and in the path of the spray emanating from said slot, said annular wall forming an annular space communicating with said preheating chamber, whereby the steam in said preheating chamber forms an annular steam wall for heating indirectly the water sprayed through said slot.

5. Apparatus for deaerating water comprising a tank having a-preheating chamber, means for introducing water into said preheating chamber, a water collecting plate affixed tothe tank walls inside the tank, a pipe suspended from said water collecting plate in communication with said preheating chamber, a distributing tray affixed to the tank walls inside the tank below said water collecting plate, support means including a water container within which said pipe is received,

- I said; support means being carried: by said. dis-- tributing tray for supporting said water collecting plate. above. said distributing. tray, a conduit fortransporting: water from said. water: container to said distributing tray, a: plurality of vertical tubes connected to receive said water from said. distributing tray, means forv introducing. steamadjacent said conduit for ultimate flow with the Water through said vertical tubes, and meansfor recycling excess: steam from said tubes to said preheating chamber.

, 6. Apparatus for. deaerating: water comprising. a tankhaving apreheating chamber, means for introducing water'into said preheating chamber, a: water collecting. plate afiixed to the tank walls inside :the'tank, a pipe suspended from said Water collectingxplate in communication with saidpreheating chamber, adistributing: tray affixed to the tank wallsi'nsidethe'tank below said water water from: said. container to said: distributing tray, a deaerator in. the: form. of. a: plurality of rigid tubes: connected to said distributing tray for: receivingv said: Water, a' plate spaced below said distributing tray fixedrto the walls of said' tank and having apertures through: which said rigid tubes extend; a conductor extending; into the tank. and. communicating. with. said. rigid tubes, for. introducing. steam along withtthe water into; said: rigid tubes, and means for recycling: excess. steam from; said tubesto saidpreheating.

chamber.

7. The invention. defined. in claim. 6;.further characterized. by the; fact that the rigid tubes terminate: abovethe: bottom of. the distributing tray. and are slotted to provide 'weirsratisubstan- ,tially a common. level controlling the flow of watersfrom the-distributing. tray into the rigid tubes.

8. An: apparatus for deaerating waterscompris ing an upper. chamber, means: forfintroducing said water. into said upper chamber, a lower chamber, a plurality of heatexchanger con-* ductors: having openings communicating with thezupper: chamber, said heat exchanger conduc tors.- having exposed" surfaces: extending down into." the. lowerfchamber, means for introducing steam into the lower chamber in direct contact with the exposedsurfaces of said heat exclianger conductors. conduit means leading from said" lower chamber: to. said; upper chamberfor conducting the'steam into the upper chamber, means;

i outer surface'of the heat exchange means'is located; means for introducing steam into said steam chamber, said steam being in direct contact with-saidouter surface; and means connecting said steam chamber to said-jet means.

10. The methodof deaerating' water in a heat exchanger? comprising passingsteam continuous-- 1y throughone side of'said'heat exchanger, continuously removing: said steam from said heat exchanger, continuously mixing said removed steam withfthe water to be deaerated, and causing the resulting. mixture to flow continuously at l downwardly with turbulence through the other side of said heat exchanger to effect deaeration of said-water in said heat exchanger, and maintainingthe incoming steam at a higher teme perature than said mixture.

11. The method of deaerating Water in a heat exchanger comprising. passing steam continuously through one' side of said heat exchanger, con- =tinuously removing said steam from said heat exchanger, continuously mixing said removed steam-with the water to 'be deaerated, and cansing, the resulting mixture to flow continuously downwardly-with turbulence through the other side of said heat'exchanger to effect deaeration of said water insaidheat exchanger, separating said: water from the mixed steam and air, and

venting said air to atmosphere.

References -C itd the 'fil Of" this patent UNITED- STATES PATENTS Number I Name Date 1,883,379" Kermarr Oct. 18, 1932 2,0783289' Sherman Apr. 27, 1937 2,308,719 Sebald'et'al'; Jali. 19, 1943 2,3031% Sebald Jan. 19, 1943 2580,791 K'ahh" Jan. 1, 1952

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